Discharge mechanism for sand classifiers



Sept. 12, 1961 THAMME 2,999,594

DISCHARGE MECHANISM FOR SAND CLASSIFIERS Filed May 27, 1959 4 Sheets-Sheet l 70 INVENTOR.

' E.P.THAMME oncg ATTORNEY Sept. 12, 1961 E. P. THAMME 2,999,594

DISCHARGE MECHANISM FOR SAND CLASSIFIERS Filed May 27, 1959 4 Sheets-Sheet 2 E.P. THAMME Mil/ENTOF? Sept. 12, 1961 E. P. THAMME 2,999,594

DISCHARGE MECHANISM FOR SAND CLASSIFIERS Filed May 27, 1959 4 Sheets-Sheet 5 FIG. l4 E.P THAMME'I VENT Sept. 12, 1961 E. P. THAMME 2,999,594

DISCHARGE MECHANISM FOR SAND CLASSIFIERS Filed May 27, 1959 4 Sheets-Sheet 4 ER THAMME- INVENTOI? United States Patent O 2,999,594 DISCHARGE MECHANISM FOR SAND CLASSIFIERS Eric P. Thamme, 58 Clinton Ave., Farmingdale, NY. Filed May 27, 1959, Ser. No. 816,182 11 Claims. (Cl. 209-462) This application is a continuation in part of my application, Serial #659,633 filed May 16, 1957 since abandoned, and relates to improvements in discharge mechanisms for classifiers such as used in the washing and grading of sand for building purposes, and more specifically it relates to discharge valves of the float-actuated, automatic control type.

This invention also relates to my patent number 2,865,503, and differs from the latter only by an improved discharge mechanism and its novel, much improved mode of operation.

Reference is hereby made to the following United States patents: Maust, 2,230,782 and Bush, 2,337,446. The art of record, excepting the patent to Bush, shows valves embedded in, and moving against, the sand. This constitutes an undesirable mode of operation due to the packing effect of the material about the valve. Bush provides a valve moving with the sand; his mechanism, however, is believed not to operate as satisfactorily for reasons which will become apparent in the course of this specification.

Inadequate control of solids, and resultant excessive head dilferential, limits the usefulness of a machine such as described in my patent mentioned supra. Adequate control results in a well-performing and reliable discharge mechanism. Proper control of solids, within and outside of a communicating riser is the subject matter of the present application which, as hereinafter will be shown, has solved the problem in a novel and unique manner.

Two bodies of water may exist independently from each other in the presence of sand so located as to constitute the dividing medium. Sand within a plain pipe serving as a communication means will elevate within this pipe as a semi-solid mass of increasing height, and until equilibrium is restored by the weight of the sand so elevated initially by the head diiferential of the two fluid levels.

To prevent the variable control water level from lowering beyond a pre-determined elevation and maintaining it at that elevation when conditions require it, is to limit the attainable head difierential, and to limit thereby the severity of the unfavorable conditions arising when not so controlled, when less water enters through the riser into the control chamber than is lost from it into the outgoing sand.

Sand within the riser exists as a column of suspension of varying density when dynamic conditions prevail; it forms into a shortened column of much higher density when the rate at which water enters into the riser lessons, and more nearly static conditions are about to prevail.

The weight of the solids within the riser and the conarea, the riser terminates within an inverted cone of space at an elevation which makes the riser self-clearing.

2,999,594 Patented Sept. 12, 1961 ice The lateral surface of the inverted cone of space inclines at the angle of repose for the material.

Ultimate control rests, of course, with a material level at a pre-determined elevation.

The main object of my invention is to provide an improved and reliable discharge mechanism for continuously and automatically controlling the material discharge rate over a wide range of operational characteristics.

Another object of my invention is to provide a dis charge mechanism which is dependable in service, is of simple construction, which is cheaply maintained, and which is inexpensive to manufacture.

Further objects and advantages of the invention will be apparent during the course of the following description, in which the accompanying drawings form a part of the specification and in which like numerals are employed throughout to designate like parts,

FIGURE 1 represents a vertical cross section through a discharge mechanism for settling classifiers embodying my invention,

FIGURE 2 is a partial, enlarged section through the auxiliary, submerged float chamber.

FIGURE 3 is a plane view of the auxiliary float chamber.

FIGURE 4 represents a partial, enlarged section of the enclosure just above the discharge valve,

FIGURE 5 illustrates another enlarged, partial section of the enclosure shown in FIGURE 4,

FIGURES 6, 11, and 12 represent vertical sections through other species of my invention,

FIGURE 7 is a partial, enlarged, sectional elevation through the float,

FIGURE 8 is an enlarged detail of the float supporting mechanism,

FIGURE 9 is a partial, enlarged, vertical section through the lower end of the valve-rod control enclosure,

FIGURE 10 is another species of discharge valve,

FIGURE 13 represents a side elevation of the species shown in FIGURE 14,

FIGURE 14 is a sectional elevation of the species shown in FIGURE 13,

FIGURE 15 represents a partial elevation of an auxiliary intake-control chamber assembly,

FIGURE 16 is a plane view of the mechanism shown in FIGURE 15,

FIGURES 17 and 18 are, respectively, enlarged elevation and plane view of the annular, auxiliary intake float in FIGURE 19, and

FIGURE 19 represents another species of my invention.

In the drawings, wherein for purposes of illustration are shown preferred embodiments of my invention, the numeral 20 designates a settling tank or receptacle with the normal water level at 21, see FIG. 1. Feed is introduced into the tank through inlet 22, overflow enters the outlet 23 on the opposite side and is Wasted. A discharge opening or underfiow outlet 24 is provided by the lower face of the discharge pipe 25 against which valve 26 is seated by rod 27 and float 28. From the float chamber 29 water drains through pipe 30, which is preferably installed as shown; it may be positioned to drain the float chamber directly.

The float chamber 29 extends above the highest attainable fiuid level 21. The bottom of the float chamber 29 constitutes the upper, conical section of riser 31 above the lower, cylindrical riser section 32, which terminates in V-shaped notches and the resultant control openings 33. The umbrella 34 is attached to the riser 32 and provides space 35 below shield 34 in the presence of sand. Above the umbrella, and attached thereto by members '36, a vertically positioned cylindrical baflle 37, defines an area of accelerated accumulation. Free space between the inner wall of the baffle 37 and the edge of umbrella 34 provides passage 38. The upper edge of the baffle is preferably serrated to modify the lateral surface of a sand cone forming during operation into a partially corruguated surface. Only in FIGURE 1 is bafl'le 37 shown serrated, even as pipe 39, which vents space 35 is shown only in FIGURE 1, either or both may be omitted if desired.

Below riser 32, pipe 40 provides passage 41 through which solids Within and adjacent to the riser move at an independent rate and without interference from sands located outside pipe 40. It is positioned co-axially with the riser 32, and is adjustably mounted by spider elements 42 and clamp 43; it comprises a vertical baflie of suitable diameter and terminates uppermost somewhat below the apex of the control openings 33. A discoid plate of suitable size 44, adjustably mounted by clamp 45, provides a horizontal balfle. It is employed to prevent channeling" and to regulate the velocity of the downwardly moving sand withing the pipe 40, relative to that of the sand outside of same.

Support for pipe 40 and disk 44 is provided by the centrally located pipe 46, spider elements 47 and flanged pass piece 48, which are welded into one assembly, which is bolted against the flanged lower end 4? of the settling tank 20.

Connecting the float chamber 29 and the submerged auxiliary float chamber 50, vertical members 51 and horizontal members 52 provide a communicating passage 53, see FIGURE 2. A removably positioned cap 54, and circumferential seal 55, secured by seal support 56, prevent the entering of water from above into the float chambers 29 and 50. Bolts or pins 57 welded to the shell 50, hold the cap 54 in place. The auxiliary float chamber 50 is vented by pipe 58 which is welded to the cap 54. The inlet pipe 59 passes through the cap 54; it is positionally secured by the rubber lined clamp 60, which latter is attached to, and is part of, cap 54. The entire float chamber assembly is removably supported by bracket 61, welded to the shell 29 and bolted against angle iron 62, rests against stop 63, and is also supported by the flanged drain pipe 30.

The auxiliary float 64 embodies a well 65 positioned co-axially with the inlet pipe 59. The letter aligns float 64 and cone valve 66. A tubular U-shaped frame 67 attaches to the underside of the float 64 and supports tubular collar 68 in which valve 66, the material of which is rubber, is removably and securely seated by tension applied by bolt 69, which passes through the lowermost member of -'the tubular frame 67.

Pipe 46, FIGURE 1, shields the valve rod 27 from the surrounding sand in the lower tank 20; it is preferably continued beyond the settled sands as high as is possible. Guides 70 for rod 27 are welded to the inner Wall of the pipe 46, a suitable distance from either end, Where they also serve as sealstops. The seals 71 are shown in FIGURE 9 to consist of sponge rubber or similarly compressible material; their exchange is facilitated by encasing the seal within a thin metallic or preferably plastic sleeve 72 so that it is secured to the inner wall of the pipe 46 by friction only, or if desired, is secured by bolts 73.

The discharge valve 26 with operating mechanism as described above will work well without a hydraulic seal, but if so desired, independently supplied water may be introduced into pipe 46 through a small pipe 75, see FIGURE 5. Drainage from the pipe 46 is provided by hole 76, see FIGURE 4. A correspondingly positioned hole, not shown, is provided near the upper end of the tube valve rod 27 to vent the pipe 46. I

In FIGURE 7, float 28 and rod 27 are shown assembled. The tubular rod 27 passes through a well 77 at the center of float 28. This well consists of a length of pipe welded to reinforcing disks 78 at the top and bottom of float. The disks 78 are welded to the float 28.

, URE l.

' adequately.

Pipe 77 extends a short distance above the float 28 where it is modified into an adjustable, self-aligning clamp 79 for valve rod 27.

Resting across the top of the control chamber 29 is placed a removably positioned stop beam 80, see FIG- URE 1. The stop beam consists of an angle iron having holes 84 at either end to engage pins 85, which are fastened to the chamber 29. Tubular member-82 supports stop plate 81 which has hol 83 for the valve rod 27 to pass through and is co-acting with the adjustably fastened stop plate on valve rod 27 by means of clamp 91 and bolts 92. A bracket 86 with fulcrum 87 carries a lever 88 with two disks at one end. The disks are positioned one or each side of the valve rod 27 and furnish a means whereby the float-valve assembly is elevated into the closed position when desired. Stops 81 and 91 respectively support the float-valve assembly when the tank is drained of its contents at the end of the day and are also the means which determine the upper limit of the underflow rate desired.

The foregoing description has been concerned with the preferred embodiment of my invention shown in FIG- In the variation shown in FIGURE 11 the serrated upper edge of the baflle 37 has been eliminated, as well as the notched lower edge of the riser 32. A skirt 101 has been provided instead of the umbrella 34 in FIGURE 1 and is fastened to the control tank 29.

In FIGURE 6 my invention is shown servicing a hindered settling, hydraulic classifier. A duct 97 with holes 96 in its upper side circles the inner wall of the settling tank 20, and furnishes a flow of water into same. The passage 98 surrounding conical portion of the control tank 29 provides drainage from the upper portion of the settling tank. A cylindrical skirt 100 with an inwardly extending flange at its upper end is adjustably fastened in the opening between the lower edge of the duct 97 and the riser 32. The remaining construction is similar to that described for FIGURE 1.

In FIGURE 12 is shown another variation of my invention in which the lower conical portion of the control tank 29 has been removed and inverted with its narrow opening 103 pointing upward. The cone 102 is fastened by bolts 105.

Another species of my invention is shown in FIGURES l3 and 14. In this species the control tank 29 has been placed outside the vertical wall of a triangular settling flume or sand tipple. The auxiliary control mechanism is placed within the tank and on the side of the main control tank 29, with which it communicates, see FIGURE 14. In its basic mode of operation, however, this species is similar to that shown in FIGURE 1.

Another species of my invention is illustrated in FIG- URE 19. This represents an extension of the one shown in FIGURE 1. The central intake flume 128 and flume discharge pipe 127 surround the vent-pipe 123 and valve stem 27 at the center of the settling tank 20. To drain freely a submerged control chamber must be vented At the bottom of the control tank 31 is fastened inner petticoat 125, which provides space 35, and outer skirt 37. The cylindrical riser section 32 is continued downwardly beyond opening 33 into the flared extension 126. In this species there is no auxiliary valve chamber for the intake of water into the'control chamber. The auxiliary inlets are built directly into the main control chamber and consist of the adjustably mounted intake pipes 59. Valves 66 are secured to the underside of the annular auxiliary float 120, which is positioned co-axially with the main float 28, as shown in detail in FIGURES 17 and 18, and the settling tank 20 is in this case provided with an overflow.

In FIGURE 10 is illustrated a flush-arresting variation of the discharge valve. The very nature of the discharge mechanism is such that it would remain open in case of failure. Outer enclosure 131, flange 132, and opening 133 in its bottom plate comprise an outer assem- 6 bly removably secured by bolts 134. The T 137, skirt 136, members 140 and support plate 138 comprise an inner assembly which moves with the discharge valve 26, and is also removably secured. In case of failure the float-valve assembly would lower abruptly until mechanically arrested and thereby would close all escape openings. Momentarily a rising fluid level in the control chamber will elevate the float-valve assembly, and thus the unit will automatically return into service. This variation of the discharge valve is not essential for satisfactory operation.

The operation of my invention is as follows:

The mode of operation will be described for the species illustrated in FIGURES l to inclusive, but the operation of the other species is exactly identical except for the minor deviations as will be explained below. To start a unit such as the one shown in FIGURE 1 in operation, it is necessary to close valve 93 and to close valve 26 by means of the lever 83 and the stop 90. With these valves closed the entire unit is filled with water until it starts to overflow through outlet 23. The valve 93 is now opened and the water begins to flow at a given velocity through the control tank and out through pipe 30. A sand and water mixture is next fed into the unit through time 22. Clay and other fine particles stay suspended and are overflowed, larger particles settle at diverse rates. Of these, particles with a settling rate inferior to the prevailing riser velocity, and chancing near the risers open end, form into a column of suspension within and above the riser 32. After the sand has collected for sometime it will build up as indicated by the dotted line in FIGURE 1 and will impede the flow of water into the control tank 29. Suspended riser solids settle back under influence of the lesser inflow rate thus brought about. The water level in the control chamber lowers, and upon passing the floats equilibrium line, will lower the float-valve assembly and open discharge valve 26, which has been previously set free through removal of pressure on lever 88. When the valve 26 opens sand will run out through same, whereupon the lower end of the control tank outlet pipe 32, with-notches 33, again becomes unimpeded, and the water level in the control tank will again rise and will close valve 26.

If valve 26 remains open for a long time too much water from the control tank 29 is lost into the outgoing sand. Therefore the water level in the control tank 29 is furthermore controlled by the auxiliary control tank 50 and the auxiliary control valve 66 which is operated by the auxiliary float 64. When the water level in the control tank 29 lowers, the water level in the auxiliary control tank 50 is lowering also, as these tanks are connected by means of a passage 53. A lowering fluid level in the control tanks will therefore lower float 64 and will open valve 66 so that water will enter through the inlet pipe 59 at any desired elevation of the control water level since the inlet pipe 59 is adjustably mounted. This secondary control water level will be automatically maintained until water enters through the riser 32 into the control chamber from below at a higher rate. The auxiliary inlet assembly provides stable conditions under which the highest production rates become possible. The umbrella 34, skirt 37, the petticoat 40 and disk 44 furnish baflles which help to control the sand around the lower end of the discharge pipe '32. from control tank 29.. It is to be noted that my invention will operate without these baflles, the operation, however, will not be as efiicient because only a nearly continuous flow will reach the maximum possible production for a given set of conditions.

The operation of the other species illustrated is basically the same as that described above except for the following minor deviations:

The one illustrated in FIGURE 6 is difierent only to the extent that an extra stream of water is introduced through the pipe 95 and duct 97 from whence it leaves through holes 96 to efliect a counter current through the normally downward flowing sand and water mixture thus acting as a hindered settling hydraulic classifier.

The species shown in FIGURES ll, 12, 13, 14, 15, and 19 are operated exactly in the same way as described for FIGURE 1, the difference being that in FIGURES ll and 12 the baffles surrounding the lower opening of the control tank 29 are somewhat different.

In the species shown in FIGURES l3 and 14, the control tank 29 is placed on the outside of the settling tank while the auxiliary control is placed in same. The operation, however, is identical to that described supra. The same is true of the species illustrated in FIGURE 19 where auxiliary control means are built into the main control tank and the same is placed centrally in the settling tank and operated similarly to what was described in FIGURE 1.

The discharge valve shown in FIGURE 10 is supplied with an inner and an outer enclosure for safer operation but operates otherwise sirnilarily to what was described supra.

It is to be understood that the form of my invention hereby described and shown, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of my invention and the scope of the subjoined claims.

It is obvious that my invention may equally well be used for the discharging of materials other than sand.

Having thus described my invention, I claim:

1. A material discharge valve construction comprising in operative combination a receptacle for material to be classified by settling, having a valved under-flow outlet and an upper overflow outlet; a control tank extending above said receptacle overflow weir and draining through a conduit leading to the atmosphere; a conduit leading from the lower control tank into the receptacle, providing communication with same and having umbrella like means above its lower limit co -operative with material accumulated in the receptacle to variably restrict flow into said control tank through said lower conduit and through a column of suspension therein; a float located in said control tank; a tubular valve stem connecting said float to a valve closing the under-flow outlet whereby operation of the valve is effected by variation of level in the control tank; an auxiliary control tank fastened on said main control tank and communicating with same through a connecting passage; an adjustable and valved auxiliary inlet pipe located below overflow level; an auxiliary float located in said auxiliary control tank; an inlet valve operated by said auxiliary float whereby the water level in said main control tank is automatically controlled; a vent-pipe extending upwardly from said umbrelladike means; a sealed, tubular enclosure concentric with said tubular valve stem; and an under-flowrate limiting adjustable stop and closing mechanism engaging said valve stem on top of said control tank.

2. A material discharge valve construction such as described in claim 1 where said main control tank has a cone-shaped lower extension terminating in a serrated short tube providing liquid communication with same; an umbrella-like horizontal shield mounted upon said short tube and carrying a serrated skirt-like open-ended cylindrical member mounted concentric with said umbrella and said short tube, surrounding said umbrella and providing an annular passage co-operative with material accumulated in the receptacle to variably restrict flow into said control tank through said annular passage, through said short tube, and through a column of suspension therein and the lower control tank; a lower openended cylindrical skirt of smaller diameter, concentric with and below the serrated lower end of said short tube extending from said control tank, adjustably mounted upon an independently secured, sealed, tubular enclosure; and a horizontally positioned discoid plate of lesser diameter concentric with and below said second skirt, adjustably mounted upon same tubular enclosure.

3. A material discharge valve construction such as described in claim 1 where said auxiliary control tank has an adjustable inlet pipe feeding said inlet valve, said inlet pipe extending upward from said inlet valve and said auxiliary tank and terminating below water level in said receptacle; and a vent pipe extending upwardly from said auxiliary control tank and terminating above the maximum water level in said settling tank.

4. A material discharge valve construction such as described in claim 1 where said main control tank has a cone-shaped lower extension terminating in a short tube; a vertical, cylindrical skirt fastened to said cone-shaped member, concentric with said short tube and terminating relative to the lower limit of said short tube; a skirt-like open-ended cylindrical member mounted concentric with and carried by said vertical, cylindrical inner skirt and said short tube providing an annular passage co-operative with material accumulated in the settling tank to variably restrict flow into said control tank through said annular passage, through said short tube, and through a column of suspension therein and the lower control tank.

5. A material discharge valve construtcion such as described in claim 1 where said main control tank has a cone-shaped lower extension terminating in a short, serrated tube providing liquid communication with same; an umbrella-like horizontal shield mounted upon said short tube relative to the lower edge of said tube, and positioned relative to and below a circular passage providing communication between an upper sizing, and a lower settling compartment in hindered settling classifiers; an open-ended, cylindrical, and flanged sleeve, vertically adjustable within said circular passage and providing in conjunction with the said umbrella an annular passage co-operative with material accumulated in-the receptacle to variably restrict flow into said control tank through said circular passage, through said annular passage, through said short tube, and through a column of suspension therein and the lower control tank; a lower open-ended cylindrical skirt of smaller diameter, concentric with and below the serrated lower end of said short tube extending from said control tank, adjustably mounted upon an independently secured, sealed, tubular enclosure; and a horizontally positioned discoid plate of lesser diameter concentric with and below said second skirt, adjustably mounted upon same tubular enclosure.

6. A material discharge valve construction such as described in claim 1 where said main control tank terminates lowermost in a cylindrical skirt of similar diameter and a conical frustum, open at top and bottom, co-operative with material accumulated in the settling tank to variably restrict flow into said control tank through said conical frustum; said frustum being fastened inside said skirt at the bottom of same.

7. A material discharge valve construction such as described in claim 1 where said main control tank is placed on the outside of said receptacle and where said auxiliary control tank is placed inside of said settling tank, said auxiliary control tank diminishing in cross-sectional area and terminating in a cylindrical discharge pipe providing liquid communication, carrying an umbrella and a surrounding co-axial skirt providing a partial annular passage co-operative with material accumulated in the settling tank to variably restn'ct flow into said control tank through said annular passage, through'said short tube, and through a column of suspension therein and the lower auxiliary control tank.

8. A material discharge valve construction such as d'e scribed in claim 1 where said main control tank has an outlet pipe with an adjustable valve whereby the continu out flow of water through said said control tanks may be adjusted at will,

9. A material discharge valve construction such as de scribed in claim 1 where said auxiliary control tank has an outlet pipe with an adjustable valve whereby the continuous flow of water through said control tanks may be adju'sted .at will.

10. A material discharge valve construction comprising a settling tank having a lower valved outlet and an upper overflow outlet; a centrally located flurne feeding said tank; a submerged control tank draining through a conduit leading from the control tank to the atmosphere; a lower conduit leading from the conical lower section of the control tank into the settling tank providing liquid communication with same, and having a flared extension below triangular inlet openings; a vertical, cylindrical skirt fastened to said conical lower section, concentric withsaid short tube and terminating relative to said inlet openings; an open-ended cylindrical baflle concentric with and carried by said vertical skirt, providing an annular passage co-operative with material accumulated in the settling tank to variably restrict flow into said control tank through said annular passage, through said lower conduit, and through a column of suspension therein and the lower control tank; a float located in said control tank; a tubular valve stem connecting said float to a valve closing the valved outlet whereby operation of the valve is effected by variation of level in the control tank; a vent pipe surrounding the upper portion of said valve rod extending from the top cover of said control tank through and to above said flume; a sealed, independently secured, tubular enclosure concentric with the lower portion of said tubular valve stem; a plurality of adjustable and valved inlet pipes terminating below settling tank water level; an auxiliary float surrounding said main float; a plurality of auxiliary inlet valves operated by said auxiliary float whereby the water level in said control tank is automatically regulated; and an adjustable stop and closing mechanism engaging said valve stem on top of said vent pipe.

11. A material discharge valve construction comprising in operative combination a receptacle having a valved underflow outlet and an upper overflow outlet; a control tank draining through a conduit to the atmosphere; a conduit leading from the lower control tank into the receptacle providing communication between said receptacle and said control tank; umbrella-like means above the lower limit of said conduit co-operative with material accumulated in the receptacle to variably restrict flow into said control tank through said conduit and through a column of suspension therein; a float located in said control tank; a tubular valve stem connecting said float to a valve closing the valved underflow out-let whereby operation of the valve is effected by variation of fluid level in the control tank; a tubular enclosure concentric with said tubular valve stem; and an underflow-rate limiting adjustable stop and closing mechanism engaging said valve stem above said control tank.

References Cited in the file of this patent UNITED STATES PATENTS 1,637,625 Shaw Aug. 2, 1927 2,337,446 Bush Dec. 21, 1943 2,425,551 McKay Aug. 12, 1947 2,537,904 McAllister Jan. 9, 1951 2,598,409 Meckenstock May 27, 1952 

